Ladder truck communication system



March 25, 195 B. A. HOSHIELD ET AL 2,828,361

LADDER TRUCK COMMUNICATION SYSTEM Filed A ri1 s, 1954 E; l

ATTORNEYS ilnited' States Patent 2,828,361 LADDER TRUCK COMMUNICATION SYSTEM Bryce A. Hoshield and Wendell H. Doan, wosso,.Mich. Application Aprils, 1954, Serial No. 421,856

3 Claims. (Cl. 179-1 The present invention relates to fire fiighting apparatus and more particularly to a ladder truck communication system permitting Constant contact between the operator of ladder controls and the fireman stationed upon the extended end of the ladder.

The efficiency of a fire fighting unit depends to a large extent upon the teamwork of the firemen. In many instances the very life of some fireman is dependent upon the activities of others. Maximum efiectiveness can only be obtained, therefore, when coordination of command and eflort areintegrated.

Modern fire fighting equipment has vastly extended the range ofladder accessibility through the development of the modernladder truck, but modern equipment has not provided collaterial equipment so as to permit coordination of effort between the operator of the ladder controls and the fireman perched precariously at the end of the ladder. Shouted commands, hand signals, and unco ordinated control of the ladder has minimized the efficiency of ladder trucks and has resulted, in some instances, in the unnecessary death or injury of the fireman stationed upon the outpost of theladder. In the 'chaos attending fires, where ladder truck equipment is useful, shouted commands are lost completely or distorted beyond reasonable value. Hand signals are next to impossible when the fireman on the ladder is involved -with hose orrescue operations. Reliance upon the operators wishes has resultedin uncoordinated action inasmuch as the ladder control operator is in no observation position to evaluate the cri-ticality of any movement of the ladder and his attentions are necessarily divided beground is involved in attending the ladder controls. The 'man in the air is involved in operations requiring the :major part of his-consoious attention. A positive liaison rbetweenthe man on the ground and the man in the air must exist and must be free from interference or dead spots? ruling out radio as a practical communication system in the ladder operation. The present apparatus and system hassolved the problem of communication between the control operator and the fireman on the ladder ffWhile avoiding the collateral difficulties encountered by reason ofpthe operating conditions.

.One of the objects of this invention, therefore, is the establishing of a communication system linking verbally the man at the controls with the fireman in the air.

Another of the objects of this invention is to premit extension and contraction of the ladder system without interfering with the'lead contacts of the communication system. H

It is another 'object'to provide apparatus assuring that no interferencewill occur between leads of the communication system and "the operation of the ladder or users of the ladder.

It is another object of this invention to provide apparatus whichis easily installed in ladder trucks without modifications of existing equipment while utilizing stand ard available components.

Other objects of this invention will become increasingly apparent to those skilled in building and using ladder truck fire fighting equipment as the description proceeds.

In the drawing:

Figure 1 is a partial side elevation view of an extension ladder fire truck illustrating the positioning of the structural components of the communication system.

Figure 2 is a perspective view of the ladder extended with one of the handrails cut away to illustrate the relative position of the structural components of the aerial ladder communication system in the extended position.

Figure 3 is a perspective fragmental view of the upper terminal portion of one of the flanged ladder legs illustrating the positioning of the plug-in outlet box and terminal portion of the tubular sleeve and leads.

Figure 4 is a perspective view of a take-up reel installed at the base of the ladder and pedestal mounted to one of the flanged ladder legs.

' trating the simultaneous wiring for the use of electrical the base of the ladder.

accessories at the'upper terminal end of the ladder.

Referring more particularly to the drawing an extension ladder fire truck 11 is shown in Fig. 1. The particular truck portion illustrated is intended to represent a schematic version of a typical ladder truck having a plurality of ladder sections 12, 13 and 14 which are extendable mechanically and controlled from panel 15 at In'general trucks 1101? this type are provided with an hydraulic cylinder 16 for raising and raising and lowering the angle of inclination of the ladder and winch and cable, or other mechanical means, are employed to extend or retract the ladders.

In order to incorporate maximum strength, resiliency, and lightness into such ladders, the legs 17 are in the shape of structural forms, usually as I-beams (as illustrated in Fig. 3) or channels having a pair of parallel inturned flanges 18 with rungs 19 attached therebetween. The importance of the flanges 18 will become increasingly evident as the description proceeds.

At the base of the ladder extension 12 a mounting plate 20 is welded'or otherwise attached to one of the legs 17, between the flanges 18. The mounting plate 20 is 'provided with mounting holes (not shown) to accommodate the positioning thereon of a take-up reel 21. The take-up reel 21 is provided with the pedestal base 22 which is attached to the mounting plate 20 to one side of the ladder section 12 and proximate to the base of the ladder section 12.

Inside the take-up reel 21 a spool is centered and axled upon a shaft provided with contactors 23 indicated schematically in Fig. 5. Lead wire or conduit 24 is coiled on the spool and the spool is spring loaded so as to impart tensional resistance to the lead wire 24 as it is payed out from the internal spool.v The take-up reel 21 employed is of the type best exemplified in United 3 States Letters Patent 1,626,376. It will be noted, however, that the take-up reel is not provided with internal locks and constant recoiling tension is applied to the lead wires 24.

Upon the uppermost stacked ladder section 14 of the extension ladder a tubular sleeve 25 is provided which is attached longitudinally to the upper flange 18 ofthe leg 17 as best illustrated in Fig. 3.

Proximate to the end of the upper extension section 14 is located a plug-in outlet box 2% provided with attac'hments for the leads 24. It is preferable that thebox 26 be of an outdoor sealed type. A manual switch 2'7 of the toggle type is inserted in the circuit, preferably on the control panel 15 where it can be available to the ladder operator for energizing the circuit.

Headphones 28 including transmitter and receiver components are provided and are shown schematically in Fig. 5.- Operational recommendations advise the use of a throat-type transmitter for the ladderman stationed upon the uppermost extension. This has been found to give the ladderman in that position a maximum amount of freedom. The headphones 28 of the operator stationed at the base of the ladder require less in the way of minimizing space and interference and any convenient transmitter can be employed. 7

At the base of the ladder extension 12 and running from the take-up reel 21, the leads 24 complete an electrical circuit as shown in Fig. 3, wherein plug-in connections are provided in the operating control panel 15 for accommodating the headset 28 of the ladder operator, and the circuit continues to close with the batterygenerator electrical system of the truck 11. The system of ground return illustrated in Fig. 5 has proved the most versatile in use, although it will be readily appreciated by those skilled in the art that a two-wire closed system can be employed. As shown in Fig. 5 a plurality of headsets 28 may be inserted depending upon the number of socket connections providedfor the jacks of the headsets. An additional lead 29 in the conduit 24 is illustrated as powering a searchlight 39 or other accessory from the lattermans normal station. Fuses 31 are preferably located adjacent the switches 27 and 27a and inject a safety element in the circuit.

From the convenient current supply of the truck 11, sufiicient power is available to power auxiliary electrical equipment on the uppermost extension 14. The provision of plural plug-in connections are illustrated in Fig. 5 at the end of the uppermost extension 14.

The headsets 23 are simply adapted to wear under standard fire fighting headgear and in accordance with known design are light and non-burdensome. Further description is thought unnecessary inasmuch as the headsets 28 are conventional equipment and in and of themselves are non-inventive. The headset leads 32 are as long as convenient and provided with plugs 33 for insertion into the sockets 34 provided.

A separate toggle switch 27a, located conveniently on the control panel 15 energizes the accessory circuit through lead 29.

In operation the aerial ladder communication system consists of a cooperating inter-relationship of the components described. The ladder operator, stationed at the base of the ladder, plugs in his headset 2% in the control panel 15. As the ladder is extended and elongate section by section the ladderman stationed on the uppermost extension 14 is .moved further away from voice contact with the operator. The ladderman plugs in his headset 28 in the plug-in box 26 provided on the uppermost ladder section 14. When the operator closes the switch 27 the ladderman and operator are in telephonic communication with each other. The reel 21 permits the paying out of wire or conduit 24 as the ladder is extended. By reason of the positioning of the take-up reel 21 the wire 24 is payed out and t-ensionally laid down adjacent the leg flange 18. Also by reason of A positioning the take up reel 21 this causes no interference with the ladder-way and being mounted on leg 17 the angular relationship between reel 21 and ladder extension 14 remains constant at all times.

On the uppermost extension 14 of the ladder, where the dimensional limitations are minimal, the tubular sleeve 25 mounted under the flange 18 confines the wire 24 and serves as a guide patterning the positioning of the wire 24 along subsequent flanged sections of the ladder. By reason of the tubular sleeve 25 no opportunity for the wire 24 to foul the ladderway is provided. The plug-in box 26 is conveniently positioned in reach of the ladderman as shown in Fig. 3.

When the headsets 28 of ladderman and operator are plugged in and the switch 27 closed, telephonic communicau'on between the operator and ladderman is direct and positive. In operation of the ladder the attention of the operator is more constantly directed to the controls while the ladderrnan, whose observation position is best, can verbally direct the movements of the ladder.

In contrast to electronic systems no fading signals have been observed and the system is not prone to dead spots which occur in radio-phone applications.

Where a plurality of plugs 33 areprovided in the plugin box 26, excellent service has been obtained by the use of a buzzer signal, a signal light, and a Searchlight inasmuch as the wiring system from the truck 11 provides a sufiicient power for useful application at the upper end of the ladder 14.

As the ladder is retracted the take-up reel 21 automatically removes slack conduit 24 from the ladderway and prevents the slack line 24 from fouling the ladderway at any time. The wire 24 is of heavy-duty type being fully insulated and having .an excess of strength over the tensional stresses applied by the take-up reel 21. At the terminal end of the tubular sleeve 25 the tube is fiared so that a minimum abrasion of the wire 24 occurs and friction between wire 24 and tube 25 is substantially eliminated. While the wire 24 goes through the tube 25, it is permanently stationed in the tube 25 and does not move in the tube 25 at all, substantially eliminating wear.

Having thus described a specific embodiment of our apparatus and communication system adaptable to ladder truck fire fighting equipment it will be understood that certain obvious modifications can be made which are intended to be embraced by the spirit of the following claims.

We claim:

1. A ladder truck control communications system extending and contracting while supplying electrical power for appliances and communication units used at the extended end of a ladder including: a power source from the ignition system of a ladder truck; a rotational ,resilient spooling element carrying a quantity of wire and connected at one end to said power source; a tube mounted adjacent one of the legs of the uppermost extension of said ladder through which said wire is passed; an outlet proximate to the uppermost end of said ladder connected to said wire; power units selectively energized by connection to said outlet; and power controls and communication elements connecting the base of the ladder with the uppermost end of the ladder while said ladder is being extended, contracted, or otherwise maneuvered.

2. In a ladder truck wherein the control of the ladder is remote from the position of the ladderman the combination including: an operators telephone headset including telephonic transmitting means and adapted for inclusion in a firefighting helmet; leads from said headset and connected to a circuit powered from the ignition system of said ladder truck; a take-up reel adapted for rotational electrical contact with said leads; a. tubular sleeve attached to one of the legs of the uppermost ladder extension; wire spooled retractably on said take-up reel a threaded through said sleeves; and a ,laddermans telephonic headset adaptable for insertion in a helmet and the leads of which are attachable to said wires completing a telephonic circuit.

3. In a ladder truck power and communication system wherein the control of the ladder is remote from the position of the ladderman the combination including: a takeup reel positioned adjacent the base of the ladder; conduits extendably and retractably on said take-up reel and attached to electrical outlets at the uppermost ladder section; headsets adaptable to insertion in the system; a separate electrical lead in said conduit making electrical power available for use at the uppermost end of the References (Iited in the file of this patent UNITED STATES PATENTS 1,435,240 Johnson Nov. 14, 1922 10 2,110,763 Gerlach Mar. 8, 1938 2,235,518 Goshaw Mar. 18. 1941 

